@article{keefer_sipple_carter_barbano_drake_2022, title={Children's perceptions of fluid milk with varying levels of milkfat}, volume={105}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2021-20826}, abstractNote={Schools participating in federal meal programs are limited to serving skim or low-fat (≤1%) flavored and unflavored milk. Few studies have directly addressed child perceptions and preferences for milk containing different amounts of milkfat. The objective of this study was to determine whether children can differentiate between flavored and unflavored fluid milk containing varying levels of milkfat and whether preferences for certain levels of milkfat exist. Flavored and unflavored milks containing 4 different percentages of milkfat (≤0.5, 1, 2, and 3.25%) were high-temperature, short-time processed, filled into half-gallon light-shielded milk jugs, and stored at 4°C in the dark. Milks were evaluated by children (ages 8-13 yr) following 7 d at 4°C. Acceptance testing and tetrad difference testing were conducted on flavored and unflavored milks with and without visual cues to determine if differences were driven by visual or flavor or mouthfeel cues. Child acceptance testing (n = 138 unflavored; n = 123 flavored) was conducted to evaluate liking and perception of selected attributes. Tetrad testing (n = 127 unflavored; n = 129 flavored) was conducted to determine if children could differentiate between different fat levels even in the absence of a difference in acceptance. The experiment was replicated twice. When visual cues were present, children had higher overall liking for 1% and 2% milks than skim for unflavored milk and higher liking for chocolate milks containing at least 1% milk fat than for skim. Differences in liking were driven by appearance, viscosity, and flavor. In the absence of visual cues, no differences were observed in liking or flavor or mouthfeel attributes for unflavored milk but higher liking for at least 1% milk fat in chocolate milk compared with skim was consistent with the presence of visual cues. From tetrad testing, children could visually tell a difference between all unflavored pairs except 2% versus whole milk and could not detect consistent differences between milkfat pairs in the absence of visual cues. For chocolate milk, children could tell a difference between all milk fat pairs with visual cues and could tell a difference between skim versus 2% and skim versus whole milk without visual cues. These results demonstrate that in the absence of package-related flavors, school-age children like unflavored skim milk as well as milk with higher fat content in the absence of visual cues. In contrast, appearance as well as flavor and mouthfeel attributes play a role in children's liking as well as their ability to discriminate between chocolate milks containing different amounts of fat, with chocolate milk containing at least 1% fat preferred. The sensory quality of school lunch milk is vital to child preference, and processing efforts are needed to maximize school milk sensory quality.}, number={4}, journal={JOURNAL OF DAIRY SCIENCE}, author={Keefer, H. M. and Sipple, L. R. and Carter, B. G. and Barbano, D. M. and Drake, M. A.}, year={2022}, month={Apr}, pages={3004–3018} }
 @article{whitt_pranata_carter_barbano_drake_2022, title={Effects of micellar casein concentrate purity and milk fat on sulfur/eggy flavor in ultrapasteurized milk-based beverages}, volume={105}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2021-21621}, abstractNote={Our objectives were to determine the level of milk-derived whey protein (MDWP) removal necessary to achieve no detectable sulfur/eggy flavor in ultrapasteurized fat-free micellar casein concentrate (MCC) beverages (6.5% protein) and in the same beverages containing 1 and 2% milk fat. Micellar casein concentrate with 95% MDWP removal was produced from skim milk (50°C) with a 3×, 3-stage ceramic microfiltration (MF) process using 0.1-µm pore size graded permeability membranes (n = 3). In experiment 1, MCC-based beverages at about 6.5% (wt/wt) true protein were formulated at a fat content of 0.15% fat (wt/wt) at 4 different levels of MDWP removal percentages (95.2%, 91.0%, 83.2%, and 69.3%). In experiment 2, a similar series of beverages at 3 MDWP removal percentages (95.2%, 83.2%, and 69.3%) with 0.1, 1, and 2% fat content were produced. The purity (or completeness of removal of whey protein by MF) of MCC was determined by the Kjeldahl method and sodium dodecyl sulfate (SDS)-PAGE. Sensory properties of beverages were documented by descriptive sensory analysis, and volatile sulfur compounds were evaluated using solid-phase microextraction followed by gas chromatography-triple quadrupole mass spectrometry. The purity of MCC measured by the Kjeldahl method (casein as a percentage of true protein) was higher after thermal treatment than before, whereas MCC purity evaluated by SDS-PAGE was unchanged by heat treatment. The purity of MCC had an effect on the flavor profile of thermally processed beverages at 6.5% protein made with fresh liquid MCC. No sulfur/eggy flavor was detected in MCC beverages when 95% of the MDWP was removed (MCC purity about 93 to 94%) from skim milk by microfiltration at 0.1, 1, and 2% fat. As the fat content of 6.5% protein beverages produced with MCC increased, sulfur/eggy flavor intensity and hydrogen sulfide concentration decreased. However, the effect of increasing milk fat on reducing sulfur/eggy flavor in MCC-based beverages at 6.5% protein was less than that of increasing MDWP removal from MCC. Sulfur off-flavors in neutral-pH dairy protein beverages can be mitigated by use of high-purity MCC or by incorporation of fat in the beverage, or both.}, number={7}, journal={JOURNAL OF DAIRY SCIENCE}, author={Whitt, D. M. and Pranata, J. and Carter, B. G. and Barbano, D. M. and Drake, M. A.}, year={2022}, month={Jul}, pages={5700–5713} }
 @article{li_choi_vuia-riser_carter_drake_zhong_2022, title={Physical and sensory properties of lemon-flavored acidic beverages formulated with nonfat dry milk during storage}, volume={105}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2021-21389}, abstractNote={Sensory and physical properties of 2 lemon-flavored beverages with 5% and 7.5% wt/wt nonfat dry milk (NFDM) at pH 2.5 were studied during storage. The 2 beverages had similar volatile compounds, but the 5% NFDM had higher aroma and lemon flavor, with a preferred appearance by consumers due to the lower turbidity and viscosity. After 28 d of storage at 4°C, lemon flavor decreased in the 5% NFDM beverage but was still more intense than the 7.5% one. During 70 d of storage, no microorganisms were detected, and the beverages were more stable when stored at 4°C than at room temperature according to changes of physical properties measured for appearance, turbidity, color, particle size, zeta potential, rheological properties, and transmission electron microscopy morphology. Findings of the present study suggest that NFDM may be used at 5% wt/wt to produce stable acidic dairy beverages with low turbidity when stored at 4°C.}, number={5}, journal={JOURNAL OF DAIRY SCIENCE}, author={Li, Nan and Choi, Inseob and Vuia-Riser, Jennifer and Carter, Brandon and Drake, MaryAnne and Zhong, Qixin}, year={2022}, month={May}, pages={3926–3938} }
 @article{carter_dimarzo_pranata_barbano_drake_2021, title={Determination of the efficiency of removal of whey protein from sweet whey with ceramic microfiltration membranes}, volume={104}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2020-18698}, abstractNote={Our research objective was to measure percent removal of whey protein from separated sweet whey using 0.1-µm uniform transmembrane pressure ceramic microfiltration (MF) membranes in a sequential batch 3-stage, 3× process at 50°C. Cheddar cheese whey was centrifugally separated to remove fat at 72°C and pasteurized (72°C for 15 s), cooled to 4°C, and held overnight. Separated whey (375 kg) was heated to 50°C with a plate heat exchanger and microfiltered using a pilot-scale ceramic 0.1-µm uniform transmembrane pressure MF system in bleed-and-feed mode at 50°C in a sequential batch 3-stage (2 diafiltration stages) process to produce a 3× MF retentate and MF permeate. Feed, retentate, and permeate samples were analyzed for total nitrogen, noncasein nitrogen, and nonprotein nitrogen using the Kjeldahl method. Sodium dodecyl sulfate-PAGE analysis was also performed on the whey feeds, retentates, and permeates from each stage. A flux of 54 kg/m2 per hour was achieved with 0.1-µm ceramic uniform transmembrane pressure microfiltration membranes at 50°C. About 85% of the total nitrogen in the whey feed passed though the membrane into the permeate. No passage of lactoferrin from the sweet whey feed of the MF into the MF permeate was detected. There was some passage of IgG, bovine serum albumen, glycomacropeptide, and casein proteolysis products into the permeate. β-Lactoglobulin was in higher concentration in the retentate than the permeate, indicating that it was partially blocked from passage through the ceramic MF membrane.}, number={7}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, Brandon and DiMarzo, Larissa and Pranata, Joice and Barbano, David M. and Drake, MaryAnne}, year={2021}, month={Jul}, pages={7534–7543} }
 @article{carter_dimarzo_pranata_barbano_drake_2021, title={Efficiency of removal of whey protein from sweet whey using polymeric microfiltration membranes}, volume={104}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2020-18771}, abstractNote={Our objective was to measure whey protein removal percentage from separated sweet whey using spiral-wound (SW) polymeric microfiltration (MF) membranes using a 3-stage, 3× process at 50°C and to compare the performance of polymeric membranes with ceramic membranes. Pasteurized, separated Cheddar cheese whey (1,080 kg) was microfiltered using a polymeric 0.3-μm polyvinylidene (PVDF) fluoride SW membrane and a 3×, 3-stage MF process. Cheese making and whey processing were replicated 3 times. There was no detectable level of lactoferrin and no intact α- or β-casein detected in the MF permeate from the 0.3-μm SW PVDF membranes used in this study. We found BSA and IgG in both the retentate and permeate. The β-lactoglobulin (β-LG) and α-lactalbumin (α-LA) partitioned between retentate and permeate, but β-LG passage through the membrane was retarded more than α-LA because the ratio of β-LG to α-LA was higher in the MF retentate than either in the sweet whey feed or the MF permeate. About 69% of the crude protein present in the pasteurized separated sweet whey was removed using a 3×, 3-stage, 0.3-μm SW PVDF MF process at 50°C compared with 0.1-μm ceramic graded permeability MF that removed about 85% of crude protein from sweet whey. The polymeric SW membranes used in this study achieve approximately 20% lower yield of whey protein isolate (WPI) and a 50% higher yield of whey protein phospholipid concentrate (WPPC) under the same MF processing conditions as ceramic MF membranes used in the comparison study. Total gross revenue from the sale of WPI plus WPPC produced with polymeric versus ceramic membranes is influenced by both the absolute market price for each product and the ratio of market price of these 2 products. The combination of the market price of WPPC versus WPI and the influence of difference in yield of WPPC and WPI produced with polymeric versus ceramic membranes yielded a price ratio of WPPC versus WPI of 0.556 as the cross over point that determined which membrane type achieves higher total gross revenue return from production of these 2 products from separated sweet whey. A complete economic engineering study comparison of the WPI and WPPC manufacturing costs for polymeric versus ceramic MF membranes is needed to determine the effect of membrane material selection on long-term processing costs, which will affect net revenue and profit when the same quantity of sweet whey is processed under various market price conditions.}, number={8}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, Brandon and DiMarzo, Larissa and Pranata, Joice and Barbano, David M. and Drake, MaryAnne}, year={2021}, month={Aug}, pages={8630–8643} }
 @article{carter_drake_2021, title={Influence of oral movement, particle size, and zeta potential on astringency of whey protein}, volume={36}, ISSN={["1745-459X"]}, DOI={10.1111/joss.12652}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF SENSORY STUDIES}, author={Carter, Brandon G. and Drake, MaryAnne}, year={2021}, month={Jun} }
 @misc{carter_cheng_kapoor_meletharayil_drake_2021, title={Invited review: Microfiltration-derived casein and whey proteins from milk}, volume={104}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2020-18811}, abstractNote={Milk, a rich source of nutrients, can be fractionated into a wide range of components for use in foods and beverages. With advancements in filtration technologies, micellar caseins and milk-derived whey proteins are now produced from skim milk using microfiltration. Microfiltered ingredients offer unique functional and nutritional benefits that can be exploited in new product development. Microfiltration offers promise in cheesemaking, where microfiltered milk can be used for protein standardization to improve the yield and consistency of cheese and help with operation throughputs. Micellar casein concentrates and milk whey proteins could offer unique functional and flavor properties in various food applications. Consumer desires for safe, nutritious, and clean-label foods could be potential growth opportunities for these new ingredients. The application of micellar casein concentrates in protein standardization could offer a window of opportunity to US cheese makers by improving yields and throughputs in manufacturing plants.}, number={3}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, B. G. and Cheng, N. and Kapoor, R. and Meletharayil, G. H. and Drake, M. A.}, year={2021}, month={Mar}, pages={2465–2479} }
 @article{choi_li_vuia-riser_carter_drake_zhong_2021, title={Neutral pH nonfat dry milk beverages with turbidity reduced by sodium hexametaphosphate: Physical and sensory properties during storage}, volume={147}, ISSN={["1096-1127"]}, DOI={10.1016/j.lwt.2021.111656}, abstractNote={There has been ascending demand on beverages enriched with dairy proteins. Calcium chelators can improve transparency and stability of beverages with nonfat dry milk (NFDM) resulting from dissociation of casein micelles. In this study, vanilla-flavored model beverages with 5% or 10% w/w NFDM were manufactured with or without 0.43% w/w sodium hexametaphosphate (SHMP), physical properties were studied during 70-day storage at 4 °C and room temperature (RT), and sensory properties were evaluated during storage at 4 °C. SHMP resulted in decreased turbidity, particle diameter, and zeta-potential magnitude. The turbidity was stable at 4 °C but increased from 161 to 315 NTU and 333 to 818 NTU, respectively, for beverages with 5% and 10% NFDM after 70-day storage at RT. SHMP resulted in insignificant and significant increase in viscosity for 5% and 10% NFDM beverage, respectively. The 10% NFDM beverage with SHMP also developed into a gel during storage at RT but remained fluidic at 4 °C. Descriptive sensory analysis suggested that SHMP resulted in soapy flavor and salty taste of beverages with decreasing vanilla and milky flavors after 70-day refrigerated storage. Findings from the present study suggest that SHMP may be used to reduce the turbidity of refrigerated beverages based on NFDM.}, journal={LWT-FOOD SCIENCE AND TECHNOLOGY}, author={Choi, Inseob and Li, Nan and Vuia-Riser, Jennifer and Carter, Brandon and Drake, MaryAnne and Zhong, Qixin}, year={2021}, month={Jul} }
 @article{vogel_carter_cheng_barbano_drake_2021, title={Ready-to-drink protein beverages: Effects of milk protein concentration and type on flavor}, volume={104}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2021-20522}, abstractNote={This study evaluated the role of protein concentration and milk protein ingredient [serum protein isolate (SPI), micellar casein concentrate (MCC), or milk protein concentrate (MPC)] on sensory properties of vanilla ready-to-drink (RTD) protein beverages. The RTD beverages were manufactured from 5 different liquid milk protein blends: 100% MCC, 100% MPC, 18:82 SPI:MCC, 50:50 SPI:MCC, and 50:50 SPI:MPC, at 2 different protein concentrations: 6.3% and 10.5% (wt/wt) protein (15 or 25 g of protein per 237 mL) with 0.5% (wt/wt) fat and 0.7% (wt/wt) lactose. Dipotassium phosphate, carrageenan, cellulose gum, sucralose, and vanilla flavor were included. Blended beverages were preheated to 60°C, homogenized (20.7 MPa), and cooled to 8°C. The beverages were then preheated to 90°C and ultrapasteurized (141°C, 3 s) by direct steam injection followed by vacuum cooling to 86°C and homogenized again (17.2 MPa first stage, 3.5 MPa second stage). Beverages were cooled to 8°C, filled into sanitized bottles, and stored at 4°C. Initial testing of RTD beverages included proximate analyses and aerobic plate count and coliform count. Volatile sulfur compounds and sensory properties were evaluated through 8-wk storage at 4°C. Astringency and sensory viscosity were higher and vanillin flavor was lower in beverages containing 10.5% protein compared with 6.3% protein, and sulfur/eggy flavor, astringency, and viscosity were higher, and sweet aromatic/vanillin flavor was lower in beverages with higher serum protein as a percentage of true protein within each protein content. Volatile compound analysis of headspace vanillin and sulfur compounds was consistent with sensory results: beverages with 50% serum protein as a percentage of true protein and 10.5% protein had the highest concentrations of sulfur volatiles and lower vanillin compared with other beverages. Sulfur volatiles and vanillin, as well as sulfur/eggy and sweet aromatic/vanillin flavors, decreased in all beverages with storage time. These results will enable manufacturers to select or optimize protein blends to better formulate RTD beverages to provide consumers with a protein beverage with high protein content and desired flavor and functional properties.}, number={10}, journal={JOURNAL OF DAIRY SCIENCE}, author={Vogel, Kenneth G., III and Carter, B. G. and Cheng, N. and Barbano, D. M. and Drake, M. A.}, year={2021}, month={Oct}, pages={10640–10653} }
 @misc{carter_foegeding_drake_2020, title={Invited review: Astringency in whey protein beverages}, volume={103}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2020-18303}, abstractNote={Astringency is the sensation of mouth drying and puckering, and it has also been described as a loss of lubrication in the mouth. Astringency is perceived as an increase in oral friction or roughness. Astringency caused by tannins and other polyphenols has been well documented and studied. Whey proteins are popular for their functional and nutritional quality, but they exhibit astringency, particularly under acidic conditions popular in high acid (pH 3.4) whey protein beverages. Acids cause astringency, but acidic protein beverages have higher astringency than acid alone. Whey proteins are able to interact with salivary proteins, which removes the lubricating saliva layer of the mouth. Whey proteins can also interact directly with epithelial tissue. These various mechanisms of astringency limit whey protein ingredient applications because astringency is undesirable to consumers. A better understanding of the causes of whey protein astringency will improve our ability to produce products that have high consumer liking and deliver excellent nutrition.}, number={7}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, B. G. and Foegeding, E. A. and Drake, M. A.}, year={2020}, month={Jul}, pages={5793–5804} }
 @article{harwood_carter_cadwallader_drake_2020, title={The role of heat treatment in light oxidation of fluid milk}, volume={103}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2020-18933}, abstractNote={Light-oxidized flavor (LOF) resulting from photooxidation of riboflavin following light exposure is one of the most common off-flavors in fluid milk. The sensory perception of LOF has been studied extensively in high temperature, short time pasteurized (HTST) milk, but few studies have evaluated ultrapasteurized (UP) milk. The objective of this study was to evaluate the role of heat treatment in the development of LOF in UP fluid skim milk. Skim milk was processed by HTST or by direct steam injection (DSI-UP) and subsequently exposed to 2,000-lx light-emitting diode light for various times. Sensory properties were monitored by descriptive analysis and threshold tests, and volatile compounds were evaluated by solid phase microextraction with gas chromatography-mass spectrometry. Dissolved oxygen and riboflavin were determined at each time point using an oxygen meter and ultra-performance liquid chromatography with a fluorescence detector, respectively. The entire experiment was performed in triplicate. Typical cardboard and mushroom flavors (LOF) were detected by trained panelists in HTST milk after 3.5 h of light exposure. In contrast, LOF was not detected by trained panelists in UP milk until 36 h of light exposure. Similarly, the best estimate threshold for LOF from untrained consumers (n = 101) was higher for DSI-UP milk (61.0 h) than for HTST milk (15.2 h). Milks with LOF were characterized by higher relative abundance of the lipid oxidation compounds hexanal and heptanal. Dissolved oxygen (DO) and riboflavin concentrations decreased with increased light exposure time, and the decrease was slower in UP milk compared with HTST milk. Initial DO concentration was investigated as a possible influence in LOF development because DSI-UP milks had lower initial DO concentrations than HTST milks. However, follow-up evaluations of deaerated HTST milks suggested that DO was not a significant factor in LOF development. These results demonstrate that UP milk is less sensitive to LOF than HTST milk, possibly due to sensory masking effects or antioxidant effects of volatile sulfur compounds. An enhanced understanding of light and storage effects on milks will assist with best practices when transporting and displaying fluid milk products for sale.}, number={12}, journal={JOURNAL OF DAIRY SCIENCE}, author={Harwood, W. S. and Carter, B. G. and Cadwallader, D. C. and Drake, M. A.}, year={2020}, month={Dec}, pages={11244–11256} }
 @article{jo_carter_barbano_drake_2019, title={Identification of the source of volatile sulfur compounds produced in milk during thermal processing}, volume={102}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2019-16607}, abstractNote={Volatile sulfur compounds in ultra-pasteurized (UP) milk are the major contributors to sulfur/burnt and eggy flavors, and these flavors are disliked by consumers. Previous research has established distinct differences in flavor profiles of fluid milk processed by high temperature, short time pasteurization (HTST) and UP by direct steam injection (DSI-UP) or indirect heat (IND-UP). An understanding of the contribution of the individual milk proteins to sulfur off-flavors would clarify the source of sulfur flavors in UP milks. The objective of this study was to determine the source of volatile sulfur compounds in fluid milk with a specific focus on the comparison of heat treatment effects on milks by HTST and UP. Formulated skim milks (FSM) were manufactured by blending micellar casein concentrate and serum protein isolate (SPI). Three different caseins as a percentage of true protein (FSM95, FSM80, and FSM60) were formulated to determine the source of sulfur/burnt and eggy flavors. Freshly processed micellar casein concentrate or SPI were blended to achieve a true protein content of about 3.2%. Raw skim milk served as a control. Skim milk and FSM were pasteurized at 78°C for 15 s (HTST) or 140°C for 2.3 s by IND-UP or DSI-UP. The experiment was replicated twice. Sensory properties of milks and FSM were documented by descriptive sensory analysis. Volatile sulfur compounds in milks and FSM were evaluated using solid-phase microextraction followed by gas chromatography-triple quadrupole mass spectrometry combined with a sulfur selective flame photometric detector. The FSM with higher SPI as a percent of true protein had higher sensory sulfur/burnt and eggy flavors along with elevated concentrations of hydrogen sulfide and carbon disulfide compared with skim milk or FSM with lower proportions of SPI. Sulfur compounds including dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, dimethyl sulfoxide, and methional were not associated with sulfur/burnt and eggy flavors, which suggests that these compounds may not specifically contribute to the sulfur/burnt and eggy off-flavors of UP milks. Sensory panelists found higher overall aroma impact, and cooked, sulfur/burnt, and eggy flavors for DSI-UP, followed by IND-UP and HTST. The combination of sensory and instrumental methods used in the current study effectively identified that milk serum proteins are the source of sulfur compounds in milk, and further confirmed the contribution of hydrogen sulfide and carbon disulfide to eggy and sulfur/burnt flavors, respectively.}, number={10}, journal={JOURNAL OF DAIRY SCIENCE}, author={Jo, Y. and Carter, B. G. and Barbano, D. M. and Drake, M. A.}, year={2019}, month={Oct}, pages={8658–8669} }
 @article{li_joyner_carter_drake_2018, title={Effects of fat content, pasteurization method, homogenization pressure, and storage time on the mechanical and sensory properties of bovine milk}, volume={101}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2017-13568}, abstractNote={Fluid milk may be pasteurized by high-temperature short-time pasteurization (HTST) or ultrapasteurization (UP). Literature suggests that UP increases milk astringency, but definitive studies have not demonstrated this effect. Thus, the objective of this study was to determine the effects of pasteurization method, fat content, homogenization pressure, and storage time on milk sensory and mechanical behaviors. Raw skim (<0.2% fat), 2%, and 5% fat milk was pasteurized in duplicate by indirect UP (140°C, 2.3 s) or by HTST pasteurization (78°C, 15 s), homogenized at 20.7 MPa, and stored at 4°C for 8 wk. Additionally, 2% fat milk was processed by indirect UP and homogenized at 13.8, 20.7, and 27.6 MPa and stored at 4°C for 8 wk. Sensory profiling, instrumental viscosity, and friction profiles of all milk were evaluated at 25°C after storage times of 1, 4, and 8 wk. Sodium dodecyl sulfate PAGE and confocal laser scanning microscopy were used to determine protein structural changes in milk at these time points. Fresh HTST milk was processed at wk 7 for wk 8 evaluations. Ultrapasteurization increased milk sensory and instrumental viscosity compared with HTST pasteurization. Increased fat content increased sensory and instrumental viscosity, and decreased astringency and friction profiles. Astringency, mixed regimen friction profiles, and sensory viscosity also increased for UP versus HTST. Increased storage time showed no effect on sensory viscosity or mechanical viscosity. However, increased storage time generally resulted in increased friction profiles and astringency. Sodium dodecyl sulfate PAGE and confocal laser scanning microscopy showed increased denatured whey protein in UP milk compared with HTST milk. The aggregates or network formed by these proteins and casein micelles likely caused the increase in viscosity and friction profiles during storage. Homogenization pressure did not significantly affect friction behaviors, mechanical viscosity, or astringency; however, samples homogenized at 13.8 MPa versus 20.7 and 27.6 MPa showed higher sensory viscosity. Astringency was positively correlated with the friction coefficient at 100 m/s sliding speed (R2 = 0.71 for HTST milk and R2 = 0.74 for UP milk), and sensory viscosity was positively correlated with the mechanical viscosity at a shear rate of 50 s-1 (R2 = 0.90). Thus, instrumental testing can be used to indicate certain sensory behaviors of milk.}, number={4}, journal={JOURNAL OF DAIRY SCIENCE}, author={Li, Y. and Joyner, H. S. and Carter, B. G. and Drake, M. A.}, year={2018}, month={Apr}, pages={2941–2955} }
 @article{carter_patel_barbano_drake_2018, title={The effect of spray drying on the difference in flavor and functional properties of liquid and dried whey proteins, milk proteins, and micellar casein concentrates}, volume={101}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2017-13780}, abstractNote={Traditionally most protein ingredients are sold as a powder due to transport ease and longer shelf life. Many high-protein powder ingredients such as milk protein concentrate with 85% protein and micellar casein concentrate have poor rehydration properties (e.g., solubility) after storage, which might limit their use. An alternative to the production of dried protein ingredients is the option to use liquid protein ingredients, which saves the cost of spray drying, but may also improve flavor and offer different functional properties. The objective of this study was to determine the effect of spray drying on the flavor and functionality of high-protein ingredients. Liquid and dried protein ingredients (whey protein concentrate with 80% protein, whey protein isolate, milk protein concentrate with 85% protein, and micellar casein concentrate) were manufactured from the same lot of milk at the North Carolina State University pilot plant. Functional differences were evaluated by measurement of foam stability and heat stability. Heat stability was evaluated by heating at 90°C for 0, 10, 20, and 30 min followed by micro-bicinchoninic acid and turbidity loss measurements. Sensory properties were evaluated by descriptive analysis, and volatile compounds were evaluated by gas chromatography-mass spectrometry. No differences were detected in protein heat stability between liquids and powders when spray dried under these conditions. Whey protein concentrate with 80% protein (liquid or spray dried) did not produce a foam. All powders had higher aroma intensity and cooked flavors compared with liquids. Powder proteins also had low but distinct cardboard flavor concurrent with higher relative abundance of volatile aldehydes compared with liquids. An understanding of how spray drying affects both flavor and functionality may help food processors better use the ingredients they have available to them.}, number={5}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, Brandon and Patel, Hasmukh and Barbano, David M. and Drake, MaryAnne}, year={2018}, month={May}, pages={3900–3909} }
 @article{carter_park_drake_2017, title={Short communication: Sensitive detection of norbixin in dried dairy ingredients at concentrations of less than 1 part per billion}, volume={100}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2017-13095}, abstractNote={Norbixin is the water-soluble carotenoid in annatto extracts used in the cheese industry to color Cheddar cheese. The purpose of norbixin is to provide cheese color, but norbixin is also present in the whey stream and contaminates dried dairy ingredients. Regulatory restrictions dictate that norbixin cannot be present in dairy ingredients destined for infant formula or ingredients entering different international markets. Thus, there is a need for the detection and quantification of norbixin at very low levels in dried dairy ingredients to confirm its absence. A rapid method for norbixin evaluation exists, but it does not have the sensitivity required to confirm norbixin absence at very low levels in compliance with existing regulations. The current method has a limit of detection of 2.7 μg/kg and a limit of quantification of 3.5 μg/kg. The purpose of this study was to develop a method to extract and concentrate norbixin for quantification in dried dairy ingredients below 1 μg/kg (1 ppb). A reverse-phase solid-phase extraction column step was applied in the new method to concentrate and quantify norbixin from liquid and dried WPC80 (whey protein concentrate with 80% protein), WPC34 (WPC, 34% protein), permeate, and lactose. Samples were evaluated by both methods for comparison. The established method was able to quantify norbixin in whey proteins and permeates (9.39 μg/kg to 2.35 mg/kg) but was unable to detect norbixin in suspect powdered lactose samples. The newly developed method had similar performance to the established method for whey proteins and permeates but was also able to detect norbixin in powdered lactose samples. The proposed method had a >90% recovery in lactose samples and a limit of detection of 28 ppt (ng/kg) and a limit of quantification of 94 ppt (ng/kg). The developed method provides detection and quantification of norbixin for dairy ingredients that have a concentration of <1 ppb.}, number={11}, journal={JOURNAL OF DAIRY SCIENCE}, author={Carter, B. G. and Park, C. W. and Drake, M. A.}, year={2017}, month={Nov}, pages={8754–8758} }